In conclusion, although multiple variants have been found associated with lung cancer risk in TERT-CLPTM1L region, our findings indicated that there are three independent lung cancer susceptibility signals in this region.
The combined analyses identified six well-replicated SNPs with independent effects and significant lung cancer associations (P < 5.0 × 10(-8)) located in TP63 (rs4488809 at 3q28, P = 7.2 × 10(-26)), TERT-CLPTM1L (rs465498 and rs2736100 at 5p15.33, P = 1.2 × 10(-20) and P = 1.0 × 10(-27), respectively), MIPEP-TNFRSF19 (rs753955 at 13q12.12, P = 1.5 × 10(-12)) and MTMR3-HORMAD2-LIF (rs17728461 and rs36600 at 22q12.2, P = 1.1 × 10(-11) and P = 6.2 × 10(-13), respectively).
Accumulating evidence has suggested that TERT could modulate the expression of numerous genes including interleukin 6 (IL-6), an important cytokine for the development of lung cancer.
We observed statistically significant associations with melanoma for two lung cancer SNPs in the TERT-CLPTM1L locus (Bonferroni-corrected p<2.8x10-4), replicating known pleiotropic effects at this locus.
We selected eight genes, ATM serine/threonine kinase gene (ATM), BRCA2, DNA repair associated gene (BRCA2), checkpoint kinase 2 gene (CHEK2), EGFR, parkin RBR E3 ubiquitin protein ligase gene (PARK2), telomerase reverse transcriptase gene (TERT), tumor protein p53 gene (TP53), and Yes associated protein 1 gene (YAP1), on the basis of prior anecdotal association with lung cancer or genome-wide association studies.
The risk of developing lung cancer in the population with the TERTrs2736098 locus carrying the T allele was 1.614 times that with the TERTrs2736098 locus carrying the C allele after adjustment of the age factor.
We conducted a search of case-control studies on the association of TERT with susceptibility to lung cancer in PubMed, EMBASE, ISI Web of Science, Wanfang database in China, and Chinese National Knowledge Infrastructure (CNKI) databases.
Various genome-wide association studies in different population groups have revealed that polymorphisms in Telomere maintenance gene (TERT) gene located on 5p15.33 is associated with susceptibility to leukemia and lung cancer risk.
The sensitivity and specificity in lung cancer diagnosis were 89.0% and 72.7% for hTERT mRNA, and 71.3% and 80.0% for EGFR mRNA, respectively. hTERT mRNA was superior to other tumor markers in lung cancer diagnosis.
DQA1*03 and the minor allele for a polymorphism, rs2736100, in TERT, another lung cancer susceptibility locus identified in recent GWASs on Europeans and Americans, were indicated to independently contribute to ADC risk with per allele OR of 1.43 (95% CI = 1.31-1.56, P = 7.8 x 10(-16)).
In the logistic regression analysis, TERT-rs2853669, rs2736108, and CLPTM1L-rs31490 were significant associated with increased risk of lung cancer (OR = 1.46, 95% CI = 1.22-1.75; OR = 1.22, 95% CI = 1.00-1.49 and OR = 1.74, 95% CI = 1.35-2.23 under additive model, respectively).